About RDA
RDA stands for Recommended Dietary Allowance, also commonly known as Recommended Daily Allowances. It is the recommended daily vitamins and mineral intake considered adequate for healthy people.

The RDA was last revised in 1989, and is rather outdated. Parts of it are replaced by the Dietary Reference Intakes (DRI), the most recent dietary guidelines by the Food and Nutrition Board of the Institute of Medicine, National Academy of Sciences, 1997-2001, in a collaboration between the US and Canada.

Food and Nutrition Board (FNB) Recommendations (#)#2 : As 10 to 30 percent of older people may malabsorb food-bound B12, FNB advises those older than 50 years to meet their Recommended Daily Allowances for it by consuming foods fortified with B12 or a supplement containing B12.

#3 : In view of evidence linking folate deficiency with neural tube defects in the fetus, FNB recommends that women capable of becoming pregnant consume 400 µg of folate from supplements or fortified foods, in addition to intake of food folate from a varied diet.

#4 : Men from 31 to 50 need slightly more magnesium (420 mg) than those from 19 to 30 years old (400 mg). Women from 31 to 50 also need slightly more magnesium (320 mg) than those from 19 to 30 years old (310 mg).

#6: Pregnant women from 31 to 50 need slightly more magnesium (360 mg) than those between 19 to 30 years old (350 mg). Women from 31 to 50 who are breastfeeding also require slightly more magnesium (320 mg) than those between 19 to 30 years old (310 mg).